[postgis-devel] Incorrect proj parameters in spatial_ref_sys?
Gary Sherman
sherman at mrcc.com
Sat Mar 26 16:35:32 PST 2005
It appears there may be an incorrect parameter in the spatial_ref_sys table
for some projections.
For example, SRID 2964 contains the proj4 parameter:
+to_meter=0.3048006096012192
When creating a layer in SRID 2964 from WGS84 (SRID 4326) using the transform
function, the coordinates are incorrect. It appears that each coordinate is
being divided by the to_meter value during transformation. This results in a
y-shift on the order of 2.8 million meters and approximately a 500K meter
x-shift. The units of the Alaska Albers projection (2964) are meters.
Dropping the to_meter parameter from the spatial_ref_sys entry results in a
correct transform.
This same behavior was noticed using ogr2ogr to transform from a geographic
shapefile to Alaska Albers.
SQL used to create the transformed table:
create table waypoints_alb as select gid, name, transform(the_geom,2964)
from waypoints_geo;
Comments -- or am I confused...
-gary
--
====================
Gary Sherman
http://mrcc.com
http://qgis.org
====================
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